This should make it easier for clients to elevate their audio threads to
real time priority without having to dig through much through specific
system internals.
This is a working implementation of a build with meson. The server,
utils, and most modules build with this, and it is possible to run from
a build tree and play/capture audio on ALSA devices.
There are a number of FIXMEs, of course, and a number of features that
need to be enabled (modules, dependencies, installation, etc.), but this
should provide everything we need to get there relatively quickly.
To use this, install meson (distro package, or mesonbuild.com) and run:
$ cd <pulseaudio src dir>
$ meson <builddir>
$ ninja -C <builddir>
Changes:
- Mention that source outputs have volume too.
- Don't claim that most distributions have flat volumes enabled.
- Volumes use a cubic scale, not logarithmic.
- Reword the warning about using the conversion functions on hardware
volumes. The old wording gave the incorrect impression that hardware
volumes could never be converted to dB or linear scale.
pa_usec_t is an unsigned type, but there were calculations that used it
as if it were a signed type.
If the latency is negative, pa_simple_get_latency() now reports 0.
Added some comments too.
The percent calculation could overflow in the pa_*volume_snprint*() functions.
For large volumes, volume * 100 can exceed UINT32_MAX.
This patch adds appropriate type casts.
When the volume exceeds PA_VOLUME_MAX in pa_sw_volume_multiply() or
pa_sw_volume_divide(), volume settings are insanely high and the
user should be notified about it.
This patch adds volume clamping to pa_sw_volume_divide() and prints
a warning when the volume is clipped in both functions.
When the specified pid no longer exists as a child of the process (since
it was already reaped by the SIGCHLD handler), errno is set to ECHILD, not
to ESRCH.
Executing below command will not produce any audio:
pacat --channels=3 /dev/urandom
Turns out that pa_stream_write() breaks large audio buffers into
segments of the maximum memblock size available -- a value which
is not necessarily frame aligned.
Meanwhile the server discards any non-aligned client audio, as a
security measure, due to some earlier reported daemon crashes.
Thus divide sent audio to the expected aligned form.
CommitReference-1: 22827a5e1e
CommitReference-2: 150ace90f3
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=98475
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=77595
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
passing an invalid sample_spec to
pa_sample_size_of_format(),
pa_frame_size(),
pa_bytes_per_second(),
pa_bytes_to_usec(),
pa_usec_to_bytes()
currently gives a result of 0
this is problematic as
(a) it leads to many potential divide-by-zero issues flagged by Coverity,
(b) pa_sample_spec_valid() is called often and the mostly unnecessary validation
of the sample_spec cannot be optimized away due to pa_return_val_if_fail()
(c) nobody checks the result for 0 and the behaviour is not documented
this patch replaces pa_return_val_if_fail() with pa_assert()
note that this commit changes the API!
note that pa_return_val_if_fail() strangely logs an assertion, but then happily
continues...
fixes numerious CIDs
json-c has a symbol clash (json_object_get_type) with json-glib (which
at least a number of our GNOME clients use). This patch moves to our own
JSON parser so that we can avoid this kind of situation altogether.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=95135
Signed-off-by: Arun Raghavan <arun@arunraghavan.net>
This reverts commit 12a202c510.
This is needed for now to avoid a clash in clients using json-glib. The
commit added a call to json_object_get_type() in client code that didn't
exist before, and this breaks some apps like Rhythmbox and Totem. This
will be fixed in the future by possibly dropping json-c as a dep.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=95135
Now that all layers in the stack support memfd blocks, add memfd
pools support for client context and audio playback data.
Use such memfd pools by default only if the server signals memfd
support in its connection negotiations.
Also add ability for clients to force-disable memfd transport
through the `enable-memfd=' client configuration option.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Now that we have the necessary infrastructure to memexport and
mempimport a memfd memblock, extend that support higher up in the
chain with pstreams.
A PA endpoint can now _transparently_ send a memfd memblock to the
other end by simply calling pa_pstream_send_memblock() – provided
the block's memfd pool was earlier registered with the pstream.
If the pipe does not support memfd transfers, we fall back to
sending the block's full data instead of just its reference.
** Further details:
A single pstream connection usually transfers blocks from multiple
pools including the server's srbchannel mempool, the client's
audio data mempool, and the server's global core mempool.
If these mempools are memfd-backed, we now require registering
them with the pstream before sending any blocks they cover. This
is done to minimize fd passing overhead and avoid fd leaks.
Moreover, to support all these pools without hard-coding their
number or nature in the Pulse communication protocol itself, a new
REGISTER_MEMFD_SHMID command is introduced. That command can be
sent _anytime_ during the pstream's lifetime and is used for
creating on demand SHM ID to memfd mappings.
Suggested-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Color global mempools with a special mark. This special marking
is needed for handling memfd-backed pools.
To avoid fd leaks, memfd pools are registered with the connection
pstream to create an ID<->memfd mapping on both PA endpoints.
Such memory regions are then always referenced by their IDs and
never by their fds, and so their fds can be safely closed later.
Unfortunately this scheme cannot work with global pools since the
registration ID<->memfd mechanism needs to happen for each newly
connected client, and thus the need for a more special handling.
That is, for the pool's fd to be always open :-(
Almost all mempools are now created on a per-client basis. The
only exception is the pa_core's mempool which is still shared
between all clients of the system.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Soon we're going to have three types of memory pools: POSIX shm_open()
pools, memfd memfd_create() ones, and privately malloc()-ed pools.
Thus introduce annotations for the memory types supported and change
pa_mempool_new() into a factory method based on required memory.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
In future commits, server-wide SHMs will be replaced with per-client
ones that will be dynamically created and freed according to clients
connections open and close.
Meanwhile, current PA design does not guarantee that the per-client
mempool blocks are referenced only by client-specific objects.
Thus reference count the pools and let each memblock inside the pool
itself, or just attached to it, increment the pool's refcount upon
allocation. This way, per-client mempools will only be freed when no
further component in the system holds any references to its blocks.
DiscussionLink: https://goo.gl/qesVMV
Suggested-by: Tanu Kaskinen <tanuk@iki.fi>
Suggested-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
This will likely be needed in the future when we start supporting high
bitrate passthrough, and there actually seem to be people 352/384 kHz
out there (potentially as an intermediate production step).
We might be compiled without eventfd support, or something else
might go wrong. And it's fully possible to continue using the old
channel rather than just disconnecting.
Signed-off-by: Pierre Ossman <ossman@cendio.se>
